The configuration of a flexible riser is extremely challenging in view of several factors including the very shallow water depth, the important offset of the vessel, the specification on the marine growth may oblige designing the configuration for two different apparent weights of the flexible riser, the restriction on the FSO structures, the requirement for perhaps 25 years of service life, and the number of the risers used.
The riser configuration proposed is installed in a water depth which is smaller than 100 m and advantageously smaller than 50 meter. No other FSO (even in Nigeria) with flexible risers connected on the sea bed has been installed in such shallow effective water depth (that is, the water depth minus the maximum draft of the vessel) combined with such extreme offset and draft change.